I had these rainbow flip flops in the eighties. Didn't everyone? Mine had blue straps, and I remember wearing the soles down into the layers of color.
I didn't have official Saltwater sandals until a few years ago, but many people have fond memories of wearing them at the shore. To me, these are the epitome of all the sturdy, buckled, flat sandals I had as a small child. And you really can get them wet! And they're made in the USA!
Huaraches, another eighties option. Remember how they'd kind of creak and squeak when you walked? This is an upscale pair from Frye. $100+ for huaraches? Criminal.
Bass Sunjuns. A classic. The pillowy suede footbeds felt so good, but always looked terrible by the end of the summer.
Kork-Ease and knock offs were everywhere for a couple of years. I had the discount store version, which featured peeling "suede" on the soles and a higher heel than I'd ever worn previously. Now you can get them with a four and half inch heel--yikes! These are awfully cute though.
Which ones do you remember wearing? Have I forgotten any?